types: add wlr_xdg_foreign_registry

include/meson.build

@@ -7,6 +7,11 @@ endif
 if conf_data.get('WLR_HAS_XWAYLAND', 0) != 1
 	exclude_files += 'xwayland.h'
 endif
+if conf_data.get('WLR_HAS_XDG_FOREIGN', 0) != 1
+	exclude_files += [
+    'types/wlr_xdg_foreign_registry.h',
+	]
+endif
 
 install_subdir('wlr',
 	install_dir: get_option('includedir'),

include/wlr/config.h.in

@@ -13,4 +13,6 @@
 #mesondefine WLR_HAS_XCB_ERRORS
 #mesondefine WLR_HAS_XCB_ICCCM
 
+#mesondefine WLR_HAS_XDG_FOREIGN
+
 #endif

include/wlr/types/wlr_xdg_foreign_registry.h

@@ -0,0 +1,75 @@
+/*
+ * This an unstable interface of wlroots. No guarantees are made regarding the
+ * future consistency of this API.
+ */
+#ifndef WLR_USE_UNSTABLE
+#error "Add -DWLR_USE_UNSTABLE to enable unstable wlroots features"
+#endif
+
+#ifndef WLR_TYPES_WLR_XDG_FOREIGN_REGISTRY_H
+#define WLR_TYPES_WLR_XDG_FOREIGN_REGISTRY_H
+
+#include <wayland-server-core.h>
+
+#define WLR_XDG_FOREIGN_HANDLE_SIZE 37
+
+/**
+ * wlr_xdg_foreign_registry is used for storing a list of exported surfaces with
+ * the xdg-foreign family of protocols.
+ *
+ * It can be used to allow interoperability between clients using different
+ * versions of the protocol (if all versions use the same registry).
+ */
+struct wlr_xdg_foreign_registry {
+	struct wl_list exported_surfaces; // struct wlr_xdg_foreign_exported_surface
+
+	struct wl_listener display_destroy;
+	struct {
+		struct wl_signal destroy;
+	} events;
+};
+
+struct wlr_xdg_foreign_exported {
+	struct wl_list link; // wlr_xdg_foreign_registry::exported_surfaces
+	struct wlr_xdg_foreign_registry *registry;
+
+	struct wlr_surface *surface;
+
+	char handle[WLR_XDG_FOREIGN_HANDLE_SIZE];
+
+	struct {
+		struct wl_signal destroy;
+	} events;
+};
+
+/**
+ * Create an empty wlr_xdg_foreign_registry.
+ *
+ * It will be destroyed when the associated display is destroyed.
+ */
+struct wlr_xdg_foreign_registry *wlr_xdg_foreign_registry_create(
+	struct wl_display *display);
+
+/**
+ * Add the given exported surface to the registry and assign it a unique handle.
+ * The caller is responsible for removing the exported surface from the repository
+ * if it is destroyed.
+ *
+ * Returns true if the initialization was successful.
+ */
+bool wlr_xdg_foreign_exported_init(struct wlr_xdg_foreign_exported *surface,
+	struct wlr_xdg_foreign_registry *registry);
+
+/**
+ * Find an exported surface with the given handle, or NULL if such a surface
+ * does not exist.
+ */
+struct wlr_xdg_foreign_exported *wlr_xdg_foreign_registry_find_by_handle(
+	struct wlr_xdg_foreign_registry *registry, const char *handle);
+
+/**
+ * Remove the given surface from the registry it was previously added in.
+ */
+void wlr_xdg_foreign_exported_finish(struct wlr_xdg_foreign_exported *surface);
+
+#endif

meson.build

@@ -87,6 +87,7 @@ conf_data.set10('WLR_HAS_X11_BACKEND', false)
 conf_data.set10('WLR_HAS_XWAYLAND', false)
 conf_data.set10('WLR_HAS_XCB_ERRORS', false)
 conf_data.set10('WLR_HAS_XCB_ICCCM', false)
+conf_data.set10('WLR_HAS_XDG_FOREIGN', false)
 
 # Clang complains about some zeroed initializer lists (= {0}), even though they
 # are valid
@@ -109,8 +110,16 @@ pixman = dependency('pixman-1')
 math = cc.find_library('m')
 rt = cc.find_library('rt')
 
-uuid = dependency('uuid', required: false)
-uuid_create = cc.has_function('uuid_create')
+if not get_option('xdg-foreign').disabled()
+	uuid = dependency('uuid', required: false)
+	uuid_create = cc.has_function('uuid_create')
+	if uuid.found() or uuid_create
+		conf_data.set10('WLR_HAS_XDG_FOREIGN', true)
+	elif get_option('xdg-foreign').enabled()
+		error('Missing dependency uuid and uuid_create function not available ' +
+				'cannot build with xdg-foreign support')
+	endif
+endif
 
 wlr_files = []
 wlr_deps = [
@@ -171,6 +180,7 @@ summary({
 	'x11_backend': conf_data.get('WLR_HAS_X11_BACKEND', 0) == 1,
 	'xcb-icccm': conf_data.get('WLR_HAS_XCB_ICCCM', 0) == 1,
 	'xcb-errors': conf_data.get('WLR_HAS_XCB_ERRORS', 0) == 1,
+	'xdg-foreign': conf_data.get('WLR_HAS_XDG_FOREIGN', 0) == 1,
 }, bool_yn: true)
 
 if get_option('examples')

meson_options.txt

@@ -7,3 +7,4 @@ option('xwayland', type: 'feature', value: 'auto', yield: true, description: 'En
 option('x11-backend', type: 'feature', value: 'auto', description: 'Enable X11 backend')
 option('examples', type: 'boolean', value: true, description: 'Build example applications')
 option('icon_directory', description: 'Location used to look for cursors (default: ${datadir}/icons)', type: 'string', value: '')
+option('xdg-foreign', type: 'feature', value: 'auto', description: 'Enable xdg-foreign protocol')

types/meson.build

@@ -66,3 +66,9 @@ wlr_files += files(
 	'wlr_xdg_decoration_v1.c',
 	'wlr_xdg_output_v1.c',
 )
+
+if conf_data.get('WLR_HAS_XDG_FOREIGN', 0) == 1
+	wlr_files += files(
+		'wlr_xdg_foreign_registry.c',
+	)
+endif

types/wlr_xdg_foreign_registry.c

@@ -0,0 +1,73 @@
+#include <wlr/types/wlr_xdg_foreign_registry.h>
+#include "util/signal.h"
+#include "util/uuid.h"
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+bool wlr_xdg_foreign_exported_init(
+		struct wlr_xdg_foreign_exported *exported,
+		struct wlr_xdg_foreign_registry *registry) {
+	do {
+		if (!generate_uuid(exported->handle)) {
+			return false;
+		}
+	} while (wlr_xdg_foreign_registry_find_by_handle(registry, exported->handle) != NULL);
+
+	exported->registry = registry;
+	wl_list_insert(&registry->exported_surfaces, &exported->link);
+
+	wl_signal_init(&exported->events.destroy);
+	return true;
+}
+
+struct wlr_xdg_foreign_exported *wlr_xdg_foreign_registry_find_by_handle(
+		struct wlr_xdg_foreign_registry *registry, const char *handle) {
+	if (handle == NULL || strlen(handle) >= WLR_XDG_FOREIGN_HANDLE_SIZE) {
+		return NULL;
+	}
+
+	struct wlr_xdg_foreign_exported *exported;
+	wl_list_for_each(exported, &registry->exported_surfaces, link) {
+		if (strcmp(handle, exported->handle) == 0) {
+			return exported;
+		}
+	}
+
+	return NULL;
+}
+
+void wlr_xdg_foreign_exported_finish(struct wlr_xdg_foreign_exported *surface) {
+	wlr_signal_emit_safe(&surface->events.destroy, NULL);
+	surface->registry = NULL;
+	wl_list_remove(&surface->link);
+	wl_list_init(&surface->link);
+}
+
+static void foreign_registry_handle_display_destroy(struct wl_listener *listener,
+		void *data) {
+	struct wlr_xdg_foreign_registry *registry =
+		wl_container_of(listener, registry, display_destroy);
+
+	wlr_signal_emit_safe(&registry->events.destroy, NULL);
+
+	// Implementations are supposed to remove all surfaces
+	assert(wl_list_empty(&registry->exported_surfaces));
+	free(registry);
+}
+
+
+struct wlr_xdg_foreign_registry *wlr_xdg_foreign_registry_create(
+		struct wl_display *display) {
+	struct wlr_xdg_foreign_registry *registry = calloc(1, sizeof(*registry));
+	if (!registry) {
+		return NULL;
+	}
+
+	registry->display_destroy.notify = foreign_registry_handle_display_destroy;
+	wl_display_add_destroy_listener(display, &registry->display_destroy);
+
+	wl_list_init(&registry->exported_surfaces);
+	wl_signal_init(&registry->events.destroy);
+	return registry;
+}

util/meson.build

@@ -8,10 +8,13 @@ wlr_files += files(
 	'time.c',
 )
 
-if uuid.found()
-	wlr_deps += uuid
-	add_project_arguments('-DHAS_LIBUUID=1', language: 'c')
-else
-	add_project_arguments('-DHAS_LIBUUID=0', language: 'c')
+
+if conf_data.get('WLR_HAS_XDG_FOREIGN', 0) == 1
+	if uuid.found()
+		wlr_deps += uuid
+		add_project_arguments('-DHAS_LIBUUID=1', language: 'c')
+	else
+		add_project_arguments('-DHAS_LIBUUID=0', language: 'c')
+	endif
+	wlr_files += files('uuid.c')
 endif
-wlr_files += files('uuid.c')